The human engineer can assemble vastly complicated structures that are completely useless until the final bit is connected up. And if he wants a better machine he can dismantle the old one, bolt on some new bits and off we go. Or simply start again from scratch using the knowledge gained from the last model.
But nature not only has no guiding hands, no workbench, it, more importantly, has to stay alive all the time a new creature is being hatched and, over evolutionary time, the chain must not be broken: every living thing today has a history of perhaps 3.5 billion years as living tissue.
So nature’s methods are going to be different to those of the engineer. And how. To make our fingers for instance, nature starts with a kind of on- piece paw-like a mitten. The bones grow from stem cells within the mitten then cells die to allow the fingers to emerge. This programmed cell death is one of nature’s key techniques. There are many more and Davies shows how complexity emerges from some very simple local rules. There is no overall plan: the body really does create itself, as the book’s subtitle says. There’s no point in multiplying examples because Davies tells the story much better than I could. This is a must-read.
And, beyond Davies’ brief for the book, human engineers are now cottoning on to nature’s technique of creating via simple local rules. Fractals were an early example: simple equations produce all those dazzling images. But fractals are 2D and nature uses simple geometry to build in 3D. Materials scientists are now showing how to do this, creating ever-more complex self-assembled structures.
Nature can never build like the human engineer but nanotechnologists and biomimeticians are showing that engineers can build it like nature.